Jean-Jacques Madeleine Willmar (French pronunciation: [ʒɑ̃ʒak madlɛn wilmaʁ]; 6 March 1792 – 20 November 1866) was a Luxembourgish politician and jurist.

[1] In 1814 he received his Licence in Law in Paris, and became a lawyer at the bar of Luxembourg city.

[1] Norbert Metz, who had become Finance Minister, and who was pro-Belgian and against membership of the German Confederation and the Zollverein, had a great influence on foreign policy, which led to tensions with Germany.

His son, William III, who had himself represented by his brother Prince Henry, led a strictly conservative and reactionary policy, and deposed the government in 1853.

Willmar's time in office saw the decision to introduce the Franc instead of the Guilder as the accounting unit of the government.